System:
* Add support for M5Stick C Plus
* Add two HTTPServer functions:
    varNames - returns list of variable names
    board - return the board type or 'none' if no board is connected
* When erasing the flash file system on ESP boards, leave time to create a new SPIFFS filesystem (takes about 75 seconds)
* Improve install of firmware on new ESP boards (i.e. boards that do not already have the MicroBlocks firmware installed)

Libraries:
* Add Websocket primitives
* Add primitives to enumerate WiFi networks (SSID's)
* Add primitive to return MAC address
* Add primitive to set TFT backlight brightness on M5 Stick C/C+
* Make microphone primitive read from the first analog pin when board has no built-in mic (thanks, José!)

Examples:
* Add Pattern memory game

Bug fixes:
* Fix: Bug in PlugShare introduced in v1.0.11
* Fix: Updating ESP boards failed when prompted by checkVmVersion
* Fix: Splitting empty string should result in the empty list
* Fix: sendVarNames should omit variables that have been deleted